Autologin isn’t something I do normally, but on my computer that run LXQt, for what they are used for, it gets the computer up faster so it is useful. If you are using LXQt with SDDM which is the default display manager, it is pretty easy to use.
Simply edit /etc/sddm.conf.d/autologin.conf and enter the following text:
[Autologin]
User=xxx
Session=lxqt.desktop
The next time you reboot the system will automatically log in.
I did previously have the desktop now running LXQt set up to just need the password and not the user name to be specified (single user login) using a custom greeter with lightdm, as it had XFCE desktop environment, but the custom greeter was disabled when I upgraded to Buster, so using the LXQt autologin capability, which is simpler to set up than with lightdm, is the next best thing. LXQt is actually easier to set up some of those automation things than some DEs are. I may end up doing a startup display customisation on this computer to work around a small issue with the monitor setup and if so then that will be very easy to do with LXQt. I am already using the autostart on the laptop to run x11vnc and having this autologin as well will eliminate the need to log in manually to it before being able to use it.